Scavenging Vacuum Pressure Provisioning with Exhaust Treatment

ABSTRACT

In one embodiment, a method that includes collecting particles from an intake flow of air for a diesel engine; removing the particles collected using scavenging vacuum pressure and without adding exhaust restriction; and treating combustion products of the diesel engine.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to copending U.S. provisionalapplication entitled, “Air Filter Aspiration and Exhaust Treatment andAspiration Fan Drive,” having Ser. No. 61/372,780, filed Aug. 11, 2010,which is entirely incorporated herein by reference.

TECHNICAL FIELD

The present disclosure is generally related to diesel engines and, moreparticularly, is related to a system and method for aspirating an airfilter assembly of a diesel engine, which uses exhaust treatment.

BACKGROUND

Utility vehicles, such as agricultural tractors, and plant machinery areoften required to work in dusty environments. In order to avoid dustentering the air intake of an internal combustion engine of such avehicle or machine, it is known to filter intake air upstream of theengine.

A typical air intake system includes, in airflow order, a pre-filter anda main filter. The pre-filter removes larger dust particles from theintake air, and then the main filter removes smaller particles. Withoutthe pre-filter, the main filter tends to clog in an unacceptably shorttime.

The particles collected by the pre-filter are typically removed byscavenging vacuum pressure that is created from engine exhaust. However,reliance on an engine exhaust system to provide such vacuum pressure canbe problematic due to various factors, such as structural complexity andback pressure being too high to accommodate additional requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with referenceto the following drawings. The components in the drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the present disclosure. Moreover, in thedrawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a schematic diagram of an example embodiment of a tractor witha diesel engine assembly.

FIG. 2 is a schematic diagram of an example embodiment of an exhausttreatment system.

FIG. 3 is a perspective view of an example embodiment of an intaketreatment system.

FIG. 4 is a flow chart depicting an example embodiment of a method foroperating a diesel engine.

FIG. 5 is a perspective view of another example embodiment of a dieselengine assembly.

FIG. 6 is a perspective view showing detail of an example embodiment ofan aspiration fan drive.

FIG. 7 is a perspective view of selected components of an exampleembodiment of an aspiration fan drive.

FIG. 8 is an assembly view of an example embodiment of an aspiration fandrive.

FIG. 9 is a flow chart depicting another example embodiment of a methodfor operating a diesel engine.

DESCRIPTION OF EXAMPLE EMBODIMENTS Overview

In one embodiment, a method that includes collecting particles from anintake flow of air for a diesel engine; removing the particles collectedusing scavenging vacuum pressure and without adding exhaust restriction;and treating combustion products of the diesel engine.

Detailed Description

As will be described in more detail below, scavenging vacuum pressurecan be provided for aspirating an air filter of a diesel engine thatimplements exhaust treatment (e.g., Selective Catalytic Reduction(SCR)). In various embodiments, this is accomplished by an idler pulleythat engages a drive belt of the engine, and which imparts rotationalspeed to a fan that produces the scavenging vacuum pressure. Notably,rotational speeds of the fan in excess of 8,000 RPM can be achieved.

The use of various exhaust treatment technologies limit the ability touse exhaust pressure to provide various functions, such as scavengingvacuum pressure. In contrast to the prior art, the use of an enginedriven idler pulley to produce scavenging vacuum pressure enables theuse of exhaust treatment with an aspirated air filter since the idlerpulley does not draw from or rely on exhaust pressure to function.Though certain embodiments described herein achieve these and/or otherbenefits, it should be understood in the context of the presentdisclosure that all of these benefits may not necessarily be providedthrough a single embodiment or realized in all embodiments describedherein.

As shown in FIG. 1, a tractor 100 includes an engine compartment 102, acab 104 and wheels, of which wheels 106 and 108 are depicted. A dieselengine assembly 110 is housed within engine compartment 102, andincludes intake treatment system 112, engine 114 and exhaust treatmentsystem 116.

Intake treatment system 112 is positioned along the flow path of intake118, which provides a flow of air to engine 114. Exhaust treatmentsystem 116 is positioned along the flow path of exhaust 120, whichdirects combustion products from engine 114.

In operation, intake treatment system 112 removes particles (e.g., dust)from a flow of air that is provided to engine 114 via intake 118 tofacilitate combustion. Thereafter, combustion products are directed toexhaust treatment system 116, which performs a catalytic reaction withthe combustion products to reduce undesirable emissions.

In FIG. 2, exhaust treatment system 116 is shown to incorporate acatalyst 122, a controller 124 and a supply 126 of additives.Specifically, catalyst 122 includes an SCR catalyst positioned withinexhaust 120 along the flow path of the combustion products. Thecombustion products are represented by arrow A. Notably, exhausttreatment system 116 functions as means for performing SCR on combustionproducts of a diesel engine.

An injector 128 is fluidicly coupled to supply 126. Injector 128selectively dispenses additives (e.g., DEF) into exhaust 120, with thedispensed additives being represented by arrow B. Notably, the additivesare dispensed within exhaust 120 and upstream of catalyst 122 tostimulate a reaction that is known to reduce various emissions such asNOx. Dispensing of the additives is performed responsive to signals fromcontroller 124, which monitors various system parameters. By way ofexample, controller 124 can monitor exhaust temperature via sensor 130.Remaining products, represented by arrow C, are directed to atmospherewith exhaust 120.

It should be noted that use of exhaust treatment system 116 increasesthe backpressure on diesel engine assembly 110 to such an extent thatexploitation of the flow of combustion products to produce vacuumpressure may not be practicable. Notably, such vacuum pressure can beused for scavenging particles from an air filter assembly that, if notremoved, could reduce the ability of the assembly to provide anappropriate volume of clean air for combustion. In this regard, FIG. 3depicts intake treatment system 112 (in greater detail), which does notrely on engine exhaust for producing scavenging vacuum pressure.

As shown in FIG. 3, intake treatment system 112 communicates with intake118. Specifically, intake treatment system 112 includes an air filterassembly 132 that removes particles from an intake flow of airrepresented by arrow D. Air filter assembly 132 then provides a flow offiltered air (represented by arrow E) to engine 114 via intake 118. Assuch, air filter assembly 132 functions as means for collectingparticles from an intake flow of air for the diesel engine.

An aspiration fan assembly 134 also is depicted in FIG. 3. Aspirationfan assembly 134 incorporates a fan 136 that is mechanically driven byengine 114 (not shown in FIG. 3) to produce scavenging vacuum pressure.The scavenging vacuum pressure is applied to air filter assembly 132 byaspiration conduit 138 to remove particles collected in air filterassembly 132 from the intake flow of air. That is, the particles aredrawn away from air filter assembly 132, through aspiration conduit 138,and toward fan 136. Thus, aspiration fan assembly 134 functions as meansfor removing the particles collected using scavenging vacuum pressureand without adding exhaust restriction to the system.

An example embodiment of a method for operating a diesel engine isdepicted in FIG. 4 that includes collecting particles from an intakeflow of air (block 140). In block 142, the particles that were collectedare removed using scavenging vacuum pressure and without adding exhaustrestriction. Then, as shown in block 144, combustion products of thediesel engine are treated. By way of example, SCR can be used.

FIG. 5 is a perspective view of another example embodiment of a dieselengine assembly 110 that includes an intake treatment system 112, anengine 114 and an exhaust treatment system 116. Intake treatment system112 is positioned along the flow path of an intake 118. Exhausttreatment system 116 is positioned along the flow path of exhaust 120and includes an SCR catalyst 122 for reacting with combustion products.

Intake treatment system 112 of FIG. 5 incorporates an air filterassembly 132 that removes particles from an intake flow of air.Specifically, air filter assembly 132 includes a pre-filter 146positioned upstream of a main filter 148. Pre-filter 146 removesparticles that are drawn into air filter assembly 132. Pre-filter 146collects these particles until scavenged as will be described later. Assuch, pre-filter 146 functions as means for pre-filtering the flow ofair.

Main filter 148 receives pre-filtered air from pre-filter 146 andremoves smaller particles from the air flow. Air filter assembly 132then provides a flow of filtered air to engine 114 via intake 118. Thus,main filter 148 functions as means for filtering the flow of air.

Aspiration fan assembly 134 incorporates a fan (not shown in FIG. 5)that is mechanically driven by engine 114 to produce scavenging vacuumpressure. The scavenging vacuum pressure is applied to air filterassembly 132 by aspiration conduit 138 to remove particles collected inair filter assembly 132. In particular, aspiration conduit 138 appliesthe scavenging vacuum pressure to pre-filter 146 to draw particlescollected by the pre-filter into the aspiration conduit such thatefficiency of air filter assembly 132 is maintained.

A more detailed view of diesel engine assembly 110 is provided by FIG.6. As shown in FIG. 6, engine 114 includes various accessories, such asan alternator 150 that is driven by an engine drive belt 152. Notably,engine drive belt 152 engages about and extends between a first pulley154, which is coupled to alternator 150, and a second pulley 156, whichis a drive pulley. Aspiration fan assembly 134 includes a compound idlerpulley 158, an outer surface of which engages an outer surface of enginedrive belt 152 to rotate compound idler pulley 158.

As shown in FIGS. 6-8, compound idler pulley 158 includes a first pulleystage 160 and a second pulley stage 162, with the first pulley stagebeing positioned to engage engine drive belt 152. Second pulley stage162 drives a fan 164 (FIG. 7) of aspiration fan assembly 134 responsiveto rotation of first pulley stage 160.

As shown most clearly in FIG. 7, first pulley stage 160 and secondpulley stage 162 are coaxial and form an integral component. Soconfigured, rotation of first pulley stage 160 results in rotation ofsecond pulley stage 162. Additionally, second pulley stage 162 exhibitsa longer radius (R₂) than the radius (R₁) of first pulley stage 160 suchthat R₂>R₁. Thus, compound idler pulley 160 functions as a means forconverting rotational motion to higher speed rotational motion.

Also depicted in FIG. 7 are fan pulley 166 and aspiration drive belt168. Aspiration drive belt 168 engages about and extends between fanpulley 166 and second pulley stage 162. Notably, second pulley stage 162exhibits a longer radius (R₂) than the radius (R₃) of fan pulley 166such that R₂>R₃. In some embodiments, second pulley stage 162 exhibits alonger radius (R₂) than the radius (R₁) of first pulley stage 160, whichalso exhibits a longer radius than the radius (R₃) of fan pulley 166(i.e., R₂>R₁>R₃). So configured, aspiration fan assembly 134 is capableof driving fan 164 at speeds in excess of 8,000 RPM. Thus, fan pulley166 is also capable of functioning as a means for converting rotationalmotion to higher speed rotational motion.

The assembly view of FIG. 8 depicts several components in greaterdetail. In this regard, compound idler pulley 158 is secured to anengine mount 170 by a bolt 172 that passes, in sequence, through spacer174, compound idler pulley 158, bearing 176, retaining ring 178 andspacer 180. Also depicted is fan support 182 that mounts stator 184,which supports axle 186 (FIG. 7) of fan 164. Stator 184 also secures fan164 to housing 188, which surrounds fan 164 and serves as a connectorfor aspiration conduit 138. An evacuation port 190 is located at base ofaspiration conduit 138 adjacent to housing 188 for expelling particlesscavenged from pre-filter 146.

FIG. 9 is a flow chart depicting another example embodiment of a methodfor operating a diesel engine that includes pre-filtering intake air toremove larger particles (block 190), and then filtering the air toremove smaller particles (block 192). In block 194, mechanically drive afan to produce the scavenging vacuum pressure, which is then applied toremove particles that were collected during pre-filtering (block 196).Notably, the fan is mechanically driven in a manner that does not addexhaust restriction. Then, as shown in block 198, SCR is performed oncombustion products of the diesel engine.

It should be emphasized that the above-described embodiments,particularly, any “preferred” embodiments, are merely possible examplesof implementations, merely set forth for a clear understanding. Manyvariations and modifications may be made to the above-describedembodiments without departing substantially from the spirit andprinciples of the disclosure. All such modifications and variations areintended to be included herein within the scope of this disclosure andprotected by the following claims.

Therefore, at least the following is claimed:
 1. A method comprising:collecting particles from an intake flow of air for a diesel engine;removing the particles collected using scavenging vacuum pressure andwithout adding exhaust restriction; and treating combustion products ofthe diesel engine.
 2. The method of claim 1, wherein removing theparticles collected using scavenging vacuum pressure further comprisesmechanically driving a fan to produce the scavenging vacuum pressure. 3.The method of claim 1, wherein removing the particles collected usingscavenging vacuum pressure further comprises converting rotationalmotion used for driving engine accessories to higher speed rotationalmotion to produce the scavenging vacuum pressure.
 4. The method of claim3, wherein converting rotational motion further comprises: driving acomponent at a first speed of rotational motion; and using the componentto generate the higher speed rotational motion.
 5. The method of claim4, wherein the component is a belt-driven component.
 6. The method ofclaim 3, wherein the converting rotational motion further comprises:driving a component at the first speed of rotational motion at a firstlocation of the component, the first location exhibiting a first radius;and generating the higher speed rotational motion at a second locationof the component exhibiting a second radius, the second radius beinglonger than the first radius.
 7. The method of claim 1, whereincollecting particles from an intake flow of air further comprisespre-filtering the air to remove larger particles, and then filtering theair to remove smaller particles.
 8. The method of claim 7, wherein, inremoving the particles collected using scavenging vacuum pressure, thescavenging vacuum pressure is directed to particles removed by thepre-filtering.
 9. The method of claim 1, wherein treating combustionproducts further comprises performing Selective Catalytic Reduction(SCR).